GEOGRAPHY

The paper examines emigration from Vietnam in the context of global climate change. Vietnam is among the five countries, most vulnerable to water level rise in the oceans associated with global warming. The areas of potential flooding include territories with most dense population and are extremity important for the economy of Vietnam. The country has a significant demographic potential exceeding 90 mln people. Vietnamese migration has a relatively long history. Large Vietnamese communities have grown in the countries of Eastern Europe; these communities are relatively well integrated into the host countries. Increase in global mean temperatures could lead to severe storms, tsunamis, and flooding and force significant portion of the population out of the Mekong Delta regions and Central provinces of Vietnam. The paper discusses the potential of Atlas Information Systems (AISs) for the assessment of social-economic and demographic consequences of climate change in Vietnam. The authors describe an AIS they are developing. This AIS consists of blocks that provide for a close link between socio-political, economic (production), natural resource, and environmental components for the integrated assessment of the provinces of Vietnam. Simulation of events shows that the flood zone could affect such populated provinces as An Giang, Kien Giang, Hau Giang, Dong Thap, Long An, Tien Giang, Vinh Long and Can Tho. To address this problem, the Vietnamese authorities, in 2008, approved the state target program to respond to climate change. The Ministry of Natural Resources and Environment was commissioned to create a scenario of climate change and sea level rise in Vietnam. However, the problem requires an immediate response at the international level, as the threat cannot be localized within the borders of Vietnam. Flooding may require mandatory relocation of the population in the country and, possibly, beyond its borders. If people are not relocated gradually, a reduction in the country’s territory with high population density, considering the specifics of the settlement pattern and reproduction trends, could result in a significant migration flow of forced migrants - environmental refugees. The territory of Vietnam may not be sufficient to absorb the entire flow of immigrants and, as a result, the flow would be directed out of the country. However, if the resettlement program starts now in the form of organized labor migration, it may be possible to anticipate and mitigate the negative scenario. Besides, organized labor emigration would be even beneficial for Vietnam in the socio-economic respect. The paper suggests measures to improve Russia’s migration policy aimed at attracting and using Vietnamese workers in a regulated way that would benefit Russia socially and economically.

The paper addresses age nonuniformity of the permafrost of the Russian Arctic shelf. It has been widely accepted that recent permafrost exists on the present-day shelf, which was formed under subaerial conditions during shelf draining in the Late Pleistocene, was flooded during the subsequent transgression, and now exists as a relic zone. However, there is also modern permafrost forming under submarine conditions. The paper considers the mechanism of its formation. The author suggests a mechanism that involves bottom soil freezing and ice formation due to constant natural transformations in seabed sediments. The proposed mechanism is supported by analyzes of certain sections of the bottom sediments of shelf and of the Pleistocene marine plains (ancient shelves) composed of dislocated sequences with massive ice beds. Analysis of the massive ground ice genesis identified different geological history as well as different transgressive and regressive regime of the Russian Arctic western and eastern sectors. The glacial cover has limited distribution in the Russian North and was absent on the Russian Arctic and Subarctic plains to the East of the Kanin Peninsula.

Agricultural lands around the globe have been seriously affected by soil erosion and resultant on- and off-site eco-environmental problems. Quantitative assessment of sediment redistribution allows for explicit understanding the effects of natural and anthropogenic agents on catchment soil erosion and sediment delivery. To this end, sediment redistribution at field and catchment scales in two agricultural regions of the Sichuan Hilly Basin in southwestern China and the Central Russian Upland was comprehensively assessed using multiple approaches including 137Cs tracing, soil morphology comparison, empirical-mathematic modeling, sediment budgeting, discharge and sediment monitoring, and sediment dating. Field measurements were undertaken in the zero-order small catchments (with drainage area less than 0,25 km2), and soil erosion rates were found to be 6-7 t ha-1-yr-1. Long-term repeated measurements indicated that both precipitation changes and conservation practices had contributed to the alleviation of soil erosion on hillslopes. However, eroded sediment was transferred from hillslopes to streams through different pathways for both regions. High slope-channel connectivity and substantial proportions of sediment delivery were observed in the Sichuan Hilly Basin. Changes of riverine suspended sediment yield were indicative of soil erosion and sediment delivery on upland catchments. Large quantity of sediment was redeposited on first-order dry-valley bottoms and only 4-12% of the gross sediment load was delivered into adjacent river channels in the Central Russian Upland.

The environmental and socio-enonomic impacts of water pollution are particularly severe in regions with relatively limited water resources [WWAP, 2012]. Water quantity and quality are closely interlinked aspects which are relevant for surface water ecology, water use, and integrated management approaches. However, an intensive monitoring of both is usually prohibitive for very large areas, particularly if it includes the investigation of underlying processes and causes. For the Kharaa - Orkhon - Selenga River system, this paper combines results from the micro (experimental plots, individual point data), meso (Kharaa River Basin) and macro (Selenge River Basin) scales. On the one hand, this integration allows an interpretation of existing data on surface water quantity and quality in a wider context. On the other hand, it empirically underpins the complimentary character of intensive monitoring in selected model regions with more extensive monitoring in larger areas.

Sutlej basin, a mountainous river basin is located in N-W Himalayan region. This basin has highest potential for hydropower generation as compared to other basins of Indus River system. Recent studies have revealed rise in mean annual surface temperature which will modify pattern of Sutlej River flow in this basin. The present paper has aimed for studying annual and seasonal patterns of river discharge at different gauging sites of Sutlej River basin (middle catchment), India. The study has been performed over three gauging sites, namely, Kasol, Sunni and Rampur located under different physiographic and climatic conditions. The daily historical records (1970-2010) of 41 years river discharge data have been employed for statistical analysis. The annual and seasonal Standardized Discharge Indices (SDI) has been derived in order to preserve uniformity and facilitate comparison between flows of Sutlej River at different sites. Mann-Kendall (MK) test, a non-parametric test method, has been applied to detect trend in annual and seasonal SDI for periods 1970-2010. Decadal (annual and seasonal) patterns in SDI have also been discussed. The results of annual and seasonal trend analysis have revealed decreasing trends in SDI at all the gauging sites. The trend in annual SDI is statistically significant (95% confidence level) at Rampur (0,04 cumec/year) and insignificant at Kasol (0,02 cumec/year) and Sunni (0,01 cumec/year) respectively. The study of annual decadal change in SDI at all the sites shows that reduction in river discharge has occurred in the decade of 2001-2010. Before this, continuous rise in annual discharge has been reported at all the sites from decades 1970-1980 to the last decade of 20th century (1991-2000). The decline in river flow may affect agriculture and electricity production as well as there may be problems related with drinking water. The present study is expected to be useful for planning water resources related projects that can be undertaken in the Sutlej basin.

The thickest loess formations, more than 100 m, are located in China and Tajikistan. Climatic and geographical factors became the basis for development of the atmospheric aerosol accumulation model in Tajikistan. Dust originated from huge deserts of the Central Asia is transported by western winds to valleys of Tajikistan where it drops out forming loess sediments. According to calculations the average thickness of dust sediments is 0,2 mm/year. This value agrees to the records obtained from loess section of the Early Holocene. Comparison of the modelling results and the real data from loess sections proves good correlation between these two independent approaches. It is one of the arguments supporting the concept of loess formation due to atmospheric aerosol.

Debris flows are the most frequent and disastrous natural hazards among other exogenic processes at the Black Sea coastal region of the North Caucasus. Numerous debris flow releases are reported every year between Novorossiysk and Krasnaya Polyana. The debris flows bring economic losses, and sometimes loss of human lives. Quantification of the economic, individual and collective debris flows risk is based on their spatial distribution, repeatability, debris flows’ regime, as well as economical and social characteristics of the territory accounted for. Estimation of the individual debris flow risk shows that the level of such risk corresponds to “allowable” and “acceptable” degrees [Vorob’ev, 2005] - less than 3,3 × 10-6. The maximal values of the economic debris flow risk are estimated in the Adler region - more than 1 mln. rub. per year.

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